1. Field of the Invention
The present invention relates to a sealing device for a pushbutton, and more particularly to a pushbutton that prevents water or dust from getting inside the pushbutton.
2. Description of Related Art
With reference to FIG. 4, a conventional sealing device for a pushbutton assembly is adapted to provide a seal between a moveable switch (20) and a button housing (40). The button housing (40) comprises a mounting sleeve (42), a retractable sleeve (44) and an elastic seal (46). The moveable switch (20) comprises an outer cover (22) and a hollow shaft (24), and the hollow shaft (24) engages the retractable sleeve (44) and attaches to the elastic seal (46). The elastic seal (46) has an outer circumference (not numbered) and an inner circumference (not numbered). An outer flange (462) is formed on the outer circumference of the elastic seal (46) and extends radially inward. An inner flange (464) is formed on the inner circumference of the elastic seal (46) and extends inward.
The button housing (40) is integrally formed with the pushbutton body (60), and the retractable sleeve (44) is securely mounted around the hollow shaft (24) of the moveable switch (20). The retractable sleeve (44) and the hollow shaft (24) are slideably engaged in the button housing (40). The mounting sleeve (42) is attached to the housing (40) with the outer flange (462) of the elastic seal (46) compressed down. Therefore, when the pushbutton is pushed down, the hollow shaft (24) pushes the retractable sleeve (44) down, which stretches the inner flange (464) of the elastic seal (46). The hollow shaft (24) holds the inner flange (464) of the elastic seal (46) down by friction and results in sealing the pushbutton. The elastic seal (46) is stretched to fit between the hollow shaft (24) and the mounting sleeve (42), but the long-lasting deformation causes permanent deformation of the elastic seal (24). The permanent deformation of the elastic seal (24) potentially allows liquid to leak into the body (60) of the pushbutton, and the life of the pushbutton is shortened.
To overcome the shortcomings, the present invention provides an improved sealing device for a pushbutton to mitigate the aforementioned problems.
The primary objective of the present invention is to provide an improved waterproof pushbutton, which comprises a body, a button housing and a cover with a hollow shaft. The body has an outer lip and an inner lip. The button housing comprises a retractable sleeve with an annular shoulder. An elastic seal is provided with inner and outer flanges and a compression fitting. With the inventive feature, the pushbutton has an advantage such as a tighter fit between the hollow shaft and the button housing that is less likely to leak.